1. Technical Field
The technical field relates to a serial interface flash memory apparatus, and particularly for the serial interface flash memory apparatus and a writing method for a status register thereof
2. Background
A status register (SR) is disposed in an NOR type flash memory with a Serial Peripheral Interface (SPI). The status register is composed of a plurality of flash memory cells and utilized to store multiple bits of data. The stored data in the status register can be read or updated through one or more accessing commands from users.
The multiple bits of data stored in the aforementioned status register include a write-protected data. The write-protected data is used to configure whether or not the memory cells in the flash memory can be updated. In the practical application of flash memory, the write-protected data in the status register is updated frequently. Since the status register is composed by a plurality of memory cells in the flash memory, the status register for storing the write-protected data is easily damaged due to the frequent update. Hence, the lifetime of the flash memory declined substantially.